Commutator.



.l. W. PEARSON.

CQMMUTATOR. Armcmou FILED an 26. ms.

Patented Sept. 10, 1918.

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/ UNITED STATES PATENT OFFICE.

JOHN PEARSON, OF CHICAGO, ILLINOIS.

COMMUTATOR.

Specification of Letters Patent.

Patented Sept. 10, 1918.

To all whom it may concern I Be it known thatl, Jenn W. PEARSON, a citizen of thel mted States of America, and

a resident of Chicago, county of Cook, and

l'leretofore one of the more prevalent means for securing the bar clamping members 1n place has been a nut and screw construction whereby upon tightl setting the nut the clamp was drawn tightly upon the insulated commutator bars or segments and the latter held in a rigid unitary manner. Subsequently, in order to simplify and cheapen the construction and to eliminate the threaded feature, the edge of one of the clamping members, namely, the commutator center, was expanded and thereby engaged with the inner edge of the outer member of cap ring, either by spinning or swaging against the main body thereof, whereby the parts were permanently locked in clampingrelation on the insulated commutator segments.

It has been found in many cases that the expanding process as applied to the commutator center has resulted in also permanently expanding the entire capring, thereby loosening the commutator bars and rendering the commutator defective.

- The main objects of this invention are to provide an improved means or form of fastening for the.clampi.ng members, adapted for locking the constituent parts rigidly to-' gether without any danger of expanding the bar engaging parts of either of. the complemental-y gripping members, or in any degree loosening the comn'ultator segments; to pro vide improved means for securing the clamping members together adapted for ready disengagement without destruetionof or injury to any of the parts in case it is desired to take the commutator apart; to provide accessible projecting or outstanding parts in registry on the clamping members which may be welded or otherwise fastened together, and may be subsequently cut away or otherwise released if desired; and to provide an outstanding peripheral flange or series of projections on one of the segment holding members adapted for engagement with the complementary member.

An illustrative embodiment of the inventlon is shown in the accompanying drawings, in which- Figurev 1 is a side view of one end of an armature equipped with the improved commutator, part of the commutator connectmg leads being removed to show certain interior details.

Fig. 2 is a cross section at AA on Fig. 1 and includes a side view of'the commutator showing the outstanding means for fastening the clamping parts together.

Fig. 3 is a longitudinal axial section through the commutator on the line 13-13 of Fig. 2.

Fig. 4; is an enlarged fragmentary view looking outward, and shows a modification consisting of a lug orprojecting tip which may be substituted for or formed on the peripheral flange or lip shown on Figs. l

- spectivcly.

In the embodiment shown in Figs. 1, 2 and 3, the commutator as a hole comprises a pair 0 complementary annular clamping members or rings 2 and 3, known as center and cap ringi, formed to wedgingly engage the commutator bars or segments 4 which are insulated from each other and from said clamping means.

' The clamping rings 2 and 3 are adapted for assembling by relative movement lengthwise of the commutator axis. They are formed to fit together telescopically and are provided with inwardly disposed complementary flanges 6 and 7 respectively adapted to Wedgingly embrace and clamp the correspondingly formed commutator segments, said flanges having inclined or frusto-conical inwardly facing surfaces, so that when the clamping rings are forced eonvergently upon said segments and suits ably fastened, the commutator parts are held rigidly in a unitary manner.

Said clamping rings 2 and 3 are provided with laterally projecting peripheral fiange-' like shoulders or lips 8 and 9 respectively in clamping position by securing said shoulders or lips together, preferably by welding while the clamp is held stationary under pressure, as in an arbor press.

In order that the commutator may be taken apart if desired, the welding is preferably limited to a series of points spaced apart, where the lips may be spot welded as indicated at 12, either by means of an electric are or a suitable gas torch, such as an oxy-acetylene burner.

In order to disengage the clamping rings it is only necessary to remove the spot welds either by filing or cutting away with a cold chisel or any other means that may be found practicable.

The removal of the fastenings or welds is most faciliated Where the fastening means is in the form of registered outstanding tips or lugs 15 which may be very easily removed (See Fig. 4). Such lugs may be formed directly on the body of the ring the spirit of the invention as defined by the following claims.

I claim 1. A commutator, comprising a plurality of conductor segments suitably insulated, and a pair of concentrically disposed thin flanged clamping members therefor formed to fit snugly one on the other and adapted for relative movement longitudinally of the axis of the commutator for assembling and taking apart, the outer member being relatively short and being positioned on one end of the other, and the flanges being disposed with their outer edges in substantially contiguous registry, said clamping members being set tightly against said segments in gripping relation thereto and being welded together at the outer edge of their abutting contiguous flange faces, the welding being spaced from the main body of the commutator by virtue of said flanges.

2. In a device of the character described, a plurality of segments grouped in annuluslike arrangement, and a pair of concentric clamping members adapted for assembling telescopically to grip said segments, one of said members being relatively short and being disposed snugly on one end of the other, said members'having corresponding flanges disposed with mutually adjacent surfaces in longitudinal alinement with the corresponding adjacent bearing surfaces respectively of said members, the edges of said flanges being disposed adjacentl when in clamping position and being wel ed together at the outer edge of their contact surfaces.

3. In a commutator, a pair of complementary clamping rings having outstanding parts arranged concentrically and in registry and welded together to secure the commutator parts rigidly together.

4. In a commutator, a series of segments and a pair of complementary clamping rings for securing said segments in alace, said rings each having a plurality of outstanding parts, those on one ring being concentric with those on the other and in mutual registry therewith respectively and secured rigidly together.

5. The method.of constructing and repairing a commutator which consists in providing outstanding complementary contiguous parts on the clamping rings, welding the outer extremities of said parts together when the commutator is assembled, removing the welds, as by chipping or filin for releasing said rings, and then rewelding said parts when the device is again assembled. 1

Signed at Chicago this 22d day of May, 1916.

JOHN W. PEARSON. 

